Viewing a single comment thread. View all comments

4tehlulzez t1_j42e90r wrote

Reply to comment by NimdokBennyandAM in How do giraffes breathe? by NimishApte

What's "dead air"?

16

mckulty t1_j42pe8t wrote

Imagine breathing through a 50-foot garden hose.

You breathe in, you might take in all the air in the hose.

You breathe out, you put that same air back into the hose.

Breathe in again, and you get the same air you breathed out but now it doesn't have much oxygen left.

By the third breath, your lungs have removed all the oxygen out of the air in the hose. The volume of air in the hose is considered "dead air" (tidal volume).

58

Vexina1997 t1_j44andl wrote

I think they're referring to what we call "dead space" in respiratory physiology, which is the part of the respiratory tract that isn't involved in oxygenation (gas exchange). Our alveoli are the only structures in our lungs that are actually exchanging gases, everything else is considered dead space (e.g. trachea, bronchus) because there is no exchange happening there. We also call those parts of the airway the conducting airway, since all they do is move air (conduction), whereas the respiratory airway refers to the alveoli since it is involved in gas exchange (respiration).

Since giraffes have very long necks and thus longer conducting airways, it would be reasonable to assume that they have much more dead space than humans do, proportionally speaking of course.

8